Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare idempotentHint=true and destructiveHint=false, so the description does not need to repeat those. It adds meaningful behavioral context: the trigger condition (must follow discovery_signup), the fact that the user receives a 6-digit code by email, and that an API key is returned on success. This goes beyond annotations, though it does not cover failure modes or rate limits, which are absent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and well-structured: a one-sentence summary, then usage context, then an Args block. Every sentence provides necessary information without fluff or redundancy. It is front-loaded with the main purpose and gives parameters in a clear list.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple two-parameter verification tool with an output schema and annotations, the description is complete. It explains the prerequisite step, the exact inputs, and the success result. Error handling is not described but is likely covered by the output schema. There are no significant gaps given the tool's complexity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0% with no descriptions, so the description carries the full burden of parameter explanation. It does so effectively: 'email: Email address used in the discovery_signup call' and 'code: 6-digit verification code from the email.' This clarifies that the email must match the prior signup call and the code is the 6-digit email code, which is exactly what the schema lacks.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: 'Complete Disco signup using an email verification code.' This uses a specific verb ('complete') and resource ('Disco signup'), and distinguishes itself from discovery_signup (which initiates) and discovery_login_verify (which is for login) by explicitly focusing on the signup verification step.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit when-to-use guidance: 'Call this after discovery_signup returns {"status": "verification_required"}.' It also instructs to use the same email address as in the signup call, clarifying the required prerequisite and input consistency. This is strong, direct usage guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.